Magnetoelectric investigations on poly(vinylidene fluoride)/NiFe2O4 flexible films fabricated through a solution casting method

Abstract

Flexible magnetoelectric polymer nanocomposite films which exhibit ferroelectric and magnetic orderings simultaneously are fabricated. Different weight percentages of NiFe₂O₄ nanoparticles (particle size of 46 nm) are embedded as fillers in a poly(vinylidene fluoride) (PVDF) matrix. A systematic investigations on the effect of the filler on the structural, functional, morphological and thermal properties are discussed. The NiFe₂O₄ content in PVDF plays a significant role in controlling the conformation (α and β phases), and therefore has a significant effect on the ferroelectric and magnetic properties of the PVDF/NiFe₂O₄ films. The coexistence of ferroelectric and ferrimagnetic ordering in the films has been shown by P–E and M–H loops. The PVDF/NiFe₂O₄ film containing a loading of 10 wt% NiFe₂O₄ nanoparticles exhibits the maximum polarization (3.07 μC cm⁻²), and represents the optimum loading required to crystallize PVDF in the ferroelectric β phase. Magnetoelectric cross-coupling has been shown to exist by controlling the electrical polarization relating to an applied magnetic field. The conduction mechanism for the observed low leakage current density has also been investigated.